Only upgrades i did were to slip flit the crank, didn't port really at all but removed casting flaws. Left transfers pretty mis matched between the jug and case and I'm sure it's hurting my power at high RPMs but I've been taking it easy on this since it's only been run 2.5 hours so far. I don't know if the straighter exhaust helps at all. After i can stand the cold enough to get to 5 or 10 hours I'm going to tear it down and put some decent bearings in it. Match the ports and transfers, dimple the piston and head and intake and transfers, sand head down to increase compression slightly. Probably shoot for like 120 psi. Probably cut the baffle down some. Will probably need to re jet as well.